I tried searching for this, but could not find anything about it so.. well, my Gamecube was working (mostly) fine until suddenly one day the Memory Card file began to stop working. All games began to say "There is an invalid device inserted into Memory Card Slot A" or something to that effect.. I also try "unplugging" and "plugging" it back in by deselecting it in the Configuration panel and reselecting it, but it still does not work.. is there any way to fix this, hopefully with any way to save my game saves?

Edit:: Dunno if this helps, but I downloaded the newest build and used the Tools to use the Memory Card Manager. When I Browse for Memory Card A and select it, it gives me the error:

well 0 bytes means everything is gone from the memory card
just delete the file and start a game with no file of that name, dolphin will create a new memory card
format it with any game and make regular backups